Ink ejectors or “jet stacks” are typically found in inkjet printers and enable controlled deposition of ink on a medium (e.g., paper) upon which printing is desired. Jet stacks are typically provided by a series of brazed steel plates, which include one or more manifolds to route ink received from ink reservoirs to an array of jets from which ink is dispensed. Jet stacks may also include transducers (e.g., piezoelectric transducers) connected to a power circuit, such that the transducers are selectively excitable. When excited, the transducers deflect, which may motivate a volume of ink to proceed through the jets and onto the medium. In this way, the deposition of the ink may be electrically controlled via the selective excitation of the transducers.
Jet stacks are generally heated to an elevated temperature to avoid solidification of the ink during its traversal through the jet stack. To accomplish such heating, jet stacks may include a heater, generally disposed between two of its plates. The heater may be an etched metal foil layer, including one or more heater traces embedded in polyimide. The heater layer is then adhered on both sides to adjacent layers utilizing two separate layers of adhesive, typically provided by acrylic-based or epoxy-based thin films.
Such adhesive layers may add cost to the jet stack and may introduce efficiency limitations, since the heater is distanced from the adjacent plates, ink body chambers, and/or other structures by the adhesive layers. Furthermore, some adhesives, such as acrylic-based adhesives, are incompatible with certain inkjet applications, e.g., printing with UV inks.
What is needed then is an apparatus and method of efficiently heating a jet stack, while reducing the size and cost associated with such jet stack heating.